Lead-bearing alloy containing copper and nickel



Patented Mar. 10, 1931 UNITED STATES PATENT OFFICE EMIL ABEL, or VIENNA, AUSTRIA, Assrenon 'IO JACOB NEURATH, or VIENNA,

AUSTRIA LEAD-BEARING ALLOY CONTAINING COPPER Ann menu.

No Drawing. Application filed November 3, 1928, Serial No. 317,108, and in Austria October 31, 1927.

My invention relates to lead bearing metals cont-aming nlckel and copper, and its fundamental feature is recognition of the fact that hearing metals containing nickel and copper formed of the usual constituents (lead, antimony and tin) with the ordinary additions of iron, cadmium, bismuth, arsenic, etc, are made especially eflicient fortheir intended purpose if, to the said alloy, non-magnetizable or so-called a-nickel exclusively is added. It is well known in the metallurgical art that nickel separates out of the melt of nickelcontaining alloys primarily as a-nickel, inasmuch as the point of conversion from nonmagnetizable into magnetizable nickel is about 320 C. (i. e. below the melting point of pure lead) but upon further cooling conversion occurs, so that in the cold nickel-con- I t-aining alloy nickel is generally present in the form of B-nickel, but it was found that this form of nickel is by far inferior in its effect on bearing metals to the a-IllCkGl.

In order to safeguard the a-nickel in the cold alloy against conversion, it is necessary that copper in addition to nickel be present and the copper must be present in a very definite weight ratio to the nickel. Above the conversion temperature of nickel, copper and a-nickel form a continuous series of mixture crystals, but below thistemperature they form a non-continuous series of mixture crystals, because in the latter case, the homogeneous field of the solid solutions of copper and a-nickel is cut by the boundary curve along which the conversion of a- B occurs, accompanied by sacrifice or loss of homogeneity. If the nickel is to exert its full efliciency,

" this latter reaction must be prevented and this is accomplished if theweight ratio of copper to nickel is such that upon cooling to room temperature, the curve above referred to is not cut. As shown by the phase diagram, the curve is not cut in the case of pure copper-nickel alloys, if the weight ratio of nickel to copper is below about 1 (in my experiments this ratio was below about 0.7) and it was found that this ratio did not change substantially, if nickel and copper are the constituents of alloys rich in lead, We

thus have the important and surprising fact that benefaction of lead bearing metals by nickel only, has its full and preponderating effect, if copper is part of the alloy and in quantity at least approximately one and one half times that of nickel. The absolute amount of copper should not-exceed about 1.5% of the entire alloy, so that the entire content of nickel may in no case exceed 1%, preferably between 0.7 to'0.8%.

Copper and nickel containing lead-bearing metals are old in the art, as shown for example by Austrian Patent No. 96,503 and British Patent No. 186,058, but the effect of unmagnetic so-called u-nickel on the properties of bearing metals and the necessity of very definitely proportioning the copper content to the nickel content in order to main tain the a-nickel were not known.

The following are examples of alloys compounded in accordance with my invention. These examples are purelyt illustrative and in no way define the scope of my invention.

Sn' Sb C11 Ni Per cent Per cmt Per cent Per cent 6 15 0.9 0.6 Remainder Pb 6 15 1.2 0.6 Remainder Pb 6 15 1.5 0.9 Remainder Pb I claim:

less than about 1.5% of copper, the amount of copper present being at least about 1.5 times the amount of nickel present.

In testimony whereof I- affix my signature.

PROF. DR. EMIL ABEL. 

